Locks, Safes, and Security: An international police reference, by Marc Weber Tobias. 4,000+ page volume of everything one could possibly hope to learn on the subject of locks and physical security within a span of a few years. There are three security clearances of this E-publication, 1-Public, 2-Locksmith, 3-Government. This is the government edition, no information is omitted. On the original CD rom set, there is included multimedia, this is ONLY a PDF version of the reading material. Don't be greedy, if you download it, upload to at least a 1:1 ratio.